Electron discharge device



Ap 20, 1943. v. L. RoNCl IELEGTBON DISCHARGE DEVICE 2 Sheets-Sheet 1 Filed Margh 20,v 1941 ATTORNEP April 20, 1943. v. L. RoNcl `ELEGTRON DISCHARGE DEVICE 2 sheets-sheet 2 Filed March 20, 1941 /NVEAl/TO/P 1./ 2. Ro/vc/ BV A Arm/wer Patented Apr. 20, 1943 ELECTRON DISCHARGE DEVICE Victor L. Ronci, Brooklyn, N. Telephone Laboratories,

Y., assignor to Bell Incorporated, New

York, N. Y., a corporation of New York Application March 20, 1941, Serial No. 384,255 4 Claims. CL Z50-27.5)

This invention relates to electron discharge devices and more particularly to such devices of high power capacity.

Electron discharge devices comprise in general a plurality of electrodes and leading-in conductors therefor which are sealed in one wall of the enclosing vessel of the device or a base secured to the vessel. The wall or base may be in whole or in part of vitreous material. In devices of high power capacity, considerable heat is developed in the electrode structure, principally in the cathode and the anode and in the leading-in conductors for the cathode, and when, as is frequently the case, the electrodes extend into proximity to the points at which the electrode leading-in conductors are sealed to the wall or base of the enclosing vessel, the heat thus developed may be of suiicient intensity to soften or even destroy the seals. In addition, in such devices, the anode may extend in proximity to the leading-in conductors for the cathode and the control electrode or grid so that the anode field deleteriously affects the operation of the device due to interaction of this eld with the input elements of the device.

One object of the invention is to eiiectively screen, both electrically and thermally, the leading-in conductors for such electrodes as the cathode and grid of an electron discharge device. More specifically objects of this invention are to shield the leading-in conductor seals in an electron discharge device from heat generated in the device during operation thereof, to electrically screen the cathode and grid leading-in conductors from the anode, and to facilitate the construction of electron discharge devices including means for thermally and electrically shielding the leading-in conductors and the seals therefor.

In one illustrative embodiment of this invention, an electron discharge device comprises a Icathode, grid and anode in coaxial relation, the anode forming a part of the enclosing vessel and the cathode and grid being supported by leading-in conductors sealed in a vitreous member which also forms a part of the enclosing vessel. These leading-in conductors are substantially enclosed in a metallic structure which is mounted on a single support sealed in the vitreous member and includes sets of batlies interposed between the electrodes and the leading-in conductor seals.

, The invention and the various features therefof will be understood more clearly and fully .119m the following detailed ydescription with reference to the accompanying drawings, in which:

Fig. 1 is an elevational view mainly in section of an electron discharge device illustrative of one embodiment of this invention;

Fig. 2 is a view along line 2-2 of Fig. -1 showing the arrangement and association of the elements of the cathode and the leading-in conductors therefor;

Fig. 3 is a detail perspective View illustrating the manner in which the cathode elements are connected to the leading-in conductors therefor; 1

Fig. 4 is another detail perspective view showing the construction of the bale and shield assembly included in the device illustrated in Fig. 1, portions of the assembly being broken away to show more clearly the members enclosed by the assembly;

Figs. 5 and 6 are detail views in section of the baille structures included in the assembly shown in Fig. 4;

Fig. 7 is a fragmentary view in perspective showing details of construction .of the grid included in the device illustrated in Fig. 1; and

Fig. 8 is a perspective View illustrating another cathode construction which may be used in the device shown in Fig. 1.

Referring now to the drawings, the electron discharge device shown in Fig.` 1 comprises an evacuated enclosing vessel having a generally pear-shaped vitreous portion IIl, a dished base Il of vitreous or ceramic material having a plurality of protuberances I2, and a metallic, e, g., copper, member including an outer wall I3 hermetically sealed to the vitreous portion III, an inwardly extending cylindrical wall I4 and a central cup-shaped portion I5 which serves as the anode of the device. Secured to the metallic portion of the enclosing vessel adjacent. the junction of the walls I3 and I4' is an annular metallic plate I6 which supports a pair of apertured, coaxial cup-shaped metallic members I'I and I8 defining with the anode I5 a chamber through which a cooling fluid may be circulated.

Mounted centrally within the anode I5 is a cathode which, in the form shown in Fig. 1, comprises a plurality, for example 12, of heavy wire, e. g., tungsten, elements I9 having reversely bent end portions I9a and mounted in parallel equally spaced relation in a cylindrical boundary. Each y of the elements I9 is secured to a rigid metallic support 20 by a coupler member 2|, the element and the corresponding support being tted in apertures 1n the coupler member, as shown in,

Figs. 1 and 3, and welded thereto. The supports 20 are grouped in threes, as shown in Figs. 2 and 3, and secured in other coupler members 22 affixed to leading-in conductors 23 sealed to the protuberances I2 on the base I I. At their other ends, the several elements I 9 are connected together mechanically and electrically by a central stud or pin 24 to Awhich they are clamped by a metallic band 25. The elements I 9, then, may be connected electrically into two groups of six, each in parallel, the connection of the cathode leading-in conductors 23 preferably being such that the direction of current flow in each of the groups of three elements I9 is opposite to that in .the-two adjacent groups of three. Y

The stud or pin 24 and band 25, it will ,be inoted,

substantially unrestrained expansion and contraction of these elements in accordance with temperature variations thereof is permitted. The reversely bent portions ISa of the velements '|19 constitute flexible links between the linear v`portions of the elements and the stud or pin 24 whereby unequal expansion and contraction of the several elements is compensated for and the parallel relation of the elements andthe cylindrical form of the-cathode boundary are preserved.

The cathode is encompassed bya grid 2S, which may be of the construction disclosed and claimed in the application Serial No. 376,564, filed January 30, 1941, of Victor L. Ronci, lcomprising -a plurality of parallel wire verticals secured at one end to a foundation member or ring 27 and Y arranged in a cylindrical boundary coaxial `with i the anode and the cathode. As shown in Fig. '7, the grid verticals may be hairpin shaped and secured at their bights between parallel metallic plates 28, the verticals being bent linwardly adjacent the `plates 28 to provide 'flexible sections .to compensate for unequal expansion and contraction of the verticals with temperature variations therein. The verticals are maintained in parallel relation during expansion and contraction thereof 4by flexible wire helices 29 each having its turns secured toalternate verticals. The foundation member or ring 21 is tted upon .and secured to a metallic ring 30 which is lsupported -by two vpairs of rigid metallic rods 3i lsecured to two of the leading-in conductors 23 bya'metall'ic coupler 32,

as shown clearly in Figs. 2 and 4. Y

' vThe ydevice disclosed and described hereinabove, asis apparent, is operable at relatively high ,power levels. When the device is operated, intense heat is developed at the electrodes and particularly at the ends thereof toward the base II .so that the various supports 'for the cathode and grid might be heated to such an extent as to shift from their intended positions and rthereby cause displacement of the grid and cathode Also theheat -radiated might be suilicient to affect deleteriously or to destroy the hermeticseals between the leading-in conductors and the 1pro'tuberances I 2 .on the base I I. To prevent these possible effects, means are provided in accordance with a feature 'of this invention to Vshield thermally the electrode supports and theseals 'from the heat radiated from the electrodes.

' In the form shown in Figs. 1 and 4, this means *is la unitary baille Vand shield structure which encloses substantially portions of 'the cathode and Vgrid supports and the Vleading-in conductors `lor these electrodes. Specically, this structure corn- Vprises Aa hollow met-allichub 33 'embedded in the base Hand overlying the exhaust tubulature 34,

acreage' l v tors 23 pass, is supported by the thimble-shaped member 31 and is connected electrically to one of the cathode leading-in conductors 23 by a me- -vtallic band 42., one end of which is clamped about are supported by the cathode elements I Q so Ythat the leading-in .conductor and the other end of which .is affixed, a-s by spot welding, to the shield 4l. The shield 4I in turn supports a cylindrical,

perforated metallic shell 43 on which there is mounted an annular baille structure including metallic plates 44 secured to one another in parallel space relation :by washer pile-ups 45 and rivets 46, .as shown clearly in Fig. '5;

It will be appreciated that thelshield and baille construction `shown .and -described eife'ctively and eillciently Vscreens the leading-in conductors, :supports and seals in the baseV II from the heat of the electrodes. The baflles -3`8 are particularly effective to shield the -seals from the heat radiated from the cathode and the leading-in conductors therefor while the lib'a'illes-Jill, `being mounted opposite the junction of the metallic walls I4 and I5, are particularly effective to protect lthe hated metallic, e. g.,

seals and leading-in conductors from the heat 'radiated bythe anode. The periora-t-ions in t-he shell 43 allow passage of lheat from the interior thereof to the wall of vessel I0 from vwhich i-t is radiated. Finally, the dished metallic member 4I because of the proximi-tyof its ybaseportion to -the seals providesheat vdissipation vfrom the region adjacent the seals. In addition, the 'shield and baille assembly constitutes an electrical screen shielding the leading-in vconductors for the cathode and the grid from the anode so that undesired interaction between the 'input ,and output elements 'of the device is 4greatly reduced. Furthermore, it will be appreciated that this construction provid-es ya unitary structure which can be assembled readily 'and facilely `mounted on the base lI I bythe single support '33.

The particular lcathode construction shown and described has been found to be `particularly advantageous.. However, other constructons may be employed if desired. One Vsuch otherconstruction ywhich may be used to advantage .is 'illustrated in FigfS and comprises a plurality of hairpin-*shaped heavy wire, e. g., tungsten, lila.- .ments 5i) formed so that the arms thereof correspond to catenaryrcurves. 'Ihegseveral laments 5!) are connected mechanically and electrically at theirb'ights by a triarmed connector 5I and have Ytheir ends -secured V.in metallic sleeves 52, which are `secured in'. turn to lami- `copper rings 53 and .'54.. As shown clearly in `Fig. 8. oneend lol each lament 55 is connected electrically vto thering -53 Vand the other end Vis ,connectedto Vring 54 so .that

It will be appreciated that .because of the catenary form of the iilaments'll,.thecathode :illustrated in VFig'. .8 will retain its form during operationof the device 'inwhlch it "is utilized whereby the requisite space relation of the cathode and the grid is preserved.

Although specic embodiments of the inven tion have been shown and described, it will be understood that they are but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising an enclosing Vessel having a hollow insulating portion and a metallic Wall extending within said insulating portion, an anode joined to the inner end of said wall, a cathode and a grid within said vessel, leading-in conductors for said cathode and grid sealed in a wall portion of said insulating portion at regions opposite the junction oi' said anode and said metallic wall, a support mounted on said insulating portion, and a unitary thermal and electrostatic shield mounted on said support and substantially enclosing said leading-in conductors, said shield comprising a portion encompassing said leading-in conductors, a metallic baiiie adjacent said junction and extending transversely between it and said wall portion and a metallic member mounted between said Wall portion and said metallic bafile.

2. An electron discharge device comprising an enclosing vessel including a dished vitreous portion, a metallic wall extending into said vitreous portion and a cylindrical anode member within said wall and connected at one end to the end of said wall within said vitreous portion, a cathode land a grid within said anode member, and each having one end opposite the base of said vitreous portion, leading-in conductors for said cathode and grid sealed in said base, and means for protecting the seals between said leading-in conductors and said base comprising a cupshaped metallic member encompassing said leading-in conductors and having its base adjacent said base of said vitreous portion, a baffle member adjacent said one end of said anode, and a second baffle member within said cup-shaped metallic member and mounted opposite the end of said cathode nearest said base of said vitreous portion.

3. An electron discharge device in accordance with claim 2 wherein said first baie member is mounted on said cup-shaped metallic member and comprising a support mounted on said vitreous portion and supporting said cup-shaped member, and a standard extending from said support and mounting said second baille member.

4. An electron discharge device comprising an enclosing vessel having a vitreous portion, a cathode, control electrode and anode each having one end opposite said vitreous portion, leading-in conductors for said cathode and control electrode sealed in said vitreous portion, a standard extending from said portion, a shield member encompassing said leading-in conductors and having a portion overlying the points at which said leading-in conductors are sealed in said vitreous portion, means supporting said shield member from said standard, a baille member mounted on said shield member and extending between said one end of said anode and said leading-in conductors, and a second baille member mounted on said standard and extending between said one end of said cathode and said vitreous portion.

VICTOR L. RONCI. 

